Terminal tractors (also referred to as spotting tractors, shunt trucks, yard trucks, yard goats, yard jockeys, or mules) are shortened versions of a conventional fifth-wheel truck and have a hydraulic lift coupled to the fifth wheel that is controllable by the operator from the truck cab. The operator can couple the fifth wheel to a trailer and engage the hydraulic lift to raise a front stand of the trailer off the underlying surface to allow movement of the trailer. The ability to raise the front stand of the trailer off the underlying surface from the truck cab allows easier and faster movement of the trailers because the operator does not have to separately raise the front stand of the trailer after it is coupled to the fifth wheel of the terminal tractor.
The prior art describes devices for elevating a fifth wheel hitch assembly mounted to a towing vehicle to engage the fifth wheel hitch assembly with the mating structures on a trailer or other component to which the fifth wheel hitch assembly is to be mated. One design pivotally couples the fifth wheel hitch assembly to an arm coupled to the frame. An actuator raises and lowers the fifth wheel hitch assembly by pivoting the arm relative to the frame.
One disadvantage of fifth wheel hitch assemblies in the prior art is that they utilize lifts that move the fifth wheel hitch assembly in an arc-shaped lift path or other non-linear lift path, which results in stresses being exerted on the fifth wheel hitch assembly and the attached trailer or implement during the mating operation or otherwise complicates the mating operation.
There is an ongoing need for advancements relating to the attachment of a fifth wheel hitch assembly to the mating structures on a trailer or other device to be connected to the fifth wheel hitch assembly and, in particular, the development of devices and methods that place less strain on the tractor drivetrain and the trailer hitch components. The present disclosure addresses this need.